NavList:

I hypothesized that my cellphone inclinometers had an "instrument error" equivalent to an index error of 33.0' off the arc.

I took three moon sights tonight in crystal clear skies, spaced one hour apart.  In each case I came up with an LOP that lay within ±4 nm of my GPS position.  I am content to say that my cellphone would serve as an adequate practice sextant, providing the raw data for doing sight reduction and plotting of moon shots.

I *was* able to see Jupiter clearly in my cellphone camera display tonight, however, the cross hairs covered the planet up if I managed to come close to centering it.  Of course, once you have covered a planet with a vertical crosshair, you don't know whether you are high or low...only that you have your bearing perfect. So I didn't bother to record an altitude.  The current generation of software (in this case, "AR Bearing") is not adequate to do star/planet sights.

Bob